Validation of a home food inventory among low-income Spanish- and Somali-speaking families

Objective: To refine and validate an existing home food inventory (HFI) for low-income Somali- and Spanish-speaking families. Design: Formative assessment was conducted using two focus groups, followed by revisions of the HFI, translation of written materials and instrument validation in participants' homes. Setting: Twin Cities Metropolitan Area, Minnesota, USA. Subjects: Thirty low-income families with children of pre-school age (fifteen Spanish-speaking; fifteen Somali-speaking) completed the HFI simultaneously with, but independently of, a trained staff member. Analysis consisted of calculation of both item-specific and average food group kappa coefficients, specificity, sensitivity and Spearman's correlation between participants' and staff scores as a means of assessing criterion validity of individual items, food categories and the obesogenic score. Results: The formative assessment revealed the need for few changes/additions for food items typically found in Spanish-speaking households. Somali-speaking participants requested few additions, but many deletions, including frozen processed food items, non-perishable produce and many sweets as they were not typical food items kept in the home. Generally, all validity indices were within an acceptable range, with the exception of values associated with items such as 'whole wheat bread' (kappa = 0.16). The obesogenic score (presence of high-fat, high-energy foods) had high criterion validity with kappa = 0.57, sensitivity = 91.8%, specificity = 70.6% and Spearman correlation = 0.78. Conclusions: The revised HFI is a valid assessment tool for use among Spanish and Somali households. This instrument refinement and validation process can be replicated with other population groups.